The present invention relates to theatre rigging equipment and specifically to lift systems for raising and lowering a load in theatrical and staging environments.
Performance venues such as theaters, arenas, concert halls, auditoriums, schools, clubs, convention centers, and television studios can employ battens or trusses to suspend, elevate, and/or lower lighting, scenery, draperies, and other equipment that can be moved relative to a stage or floor. Such battens can include pipe or joined pipe sections that form a desired length of the batten. Battens can be 50 feet or more in length. To support heavy loads or suspension points are that spaced apart (e.g., 15-30 feet apart), the battens may be fabricated in various configurations, such as ladder, triangular, or box truss configurations. A number of elevating or hoisting or lift systems are available for supporting, raising, and lowering battens and/or articles used in such venues.
One such lift system utilizes elongated flexible members, such as cables, to provide movement to the batten. Loft blocks are commonly mounted above the stage to facilitate directing the cables from a horizontal orientation to a vertical orientation. Lift systems of this type are disclosed in U.S. Pat. No. 8,033,528; U.S. Pat. No. 7,775,506; U.S. Patent Application Publication No. 2009/0127527, and International Patent Application Publication No. WO 2011/063141. The entire contents of each of the above-reference patent applications is hereby incorporated by reference herein in their entirety.